Police say he also contacted the teen girls on Facebook inappropriately.

Additionally, police say Bauer admitted to going to parties with students when their parents weren't home, and he'd bring beer.

Police say they began the investigation Wednesday, following a tip from the school given to them by another student.

Bauer has been a teacher at St. Lucie West Centennial High School since 2008.

"I mean, he's 34. He knew what he was doing," said student Lindsey Parent.

Students say he was a favorite teacher for many.

"He didn't want to be known as like 'the teacher', he wanted to be cool and hang out with them," said former student, Madison Scherer.

Scherer says he also chaperones a Key West trip for the students, which she attended.

Parents are concerned after hearing the news. "I think with social media, everybody is a little too free nowadays. I think teachers acting like that is very concerning. The kids are one thing, but when the teachers get involved, that's another," said parent Dawn Ogonowski.

Bauer is the 4th St. Lucie County School District staff member to be arrested this year for inappropriate contact with a student.

"It does seem unusual that this year, we've had so many in St. Lucie County. But I don't know any specific reason for that," said Port St. Lucie detective

The school district released this statement saying in part, “The St. Lucie County Public Schools’ primary concern is always the safety, security and welfare of all students we serve. The St. Lucie West Centennial High School employee is not assigned to campus at this time. This is a criminal law enforcement investigation and employees will proceed through the established process.

The school also says it reviews the Florida code of ethics with staff every year, and will be going over it again with staff.

Police say they are continuing to investigate whether there are any more victims.